.backtop {
    z-index: 101;
    bottom: 155px;
    position: fixed;
    right: 0px;
    margin-right: 35px;
    cursor: pointer;
    & .bt-box {
        padding: 11px 12px;
        margin-bottom: 5px;
        width: 42px;
        height: 42px;
        line-height: 18px;
        vertical-align: middle;
        background: #5087F0;
        -webkit-box-sizing: border-box;
        -moz-box-sizing: border-box;
        box-sizing: border-box;
        border-radius: 2px;
        box-shadow: 0 1px 1px rgba(0,0,0,0.04);
        text-align: center;
        & i {
            color: white;
            font-size: 1.2em;
            font-weight: bold;
        }
    }
}